In twisting spindles for multiple yarns or yarns of a conventional design the rotating spindle portion (spindle rotor) is provided with a yarn storage disk about the periphery of which the yarn exiting radially from the hollow spindle shaft is collected with a greater or lesser length before the yarn under ballooning is guided to a yarn guide located on an extension of the spindle axis and further to a removal device or directly to a winding device. The yarn storage disk has the purpose of receiving between the radial outlet of the yarn from the spindle and the balloon to provide for a certain yarn reservoir that ensures a uniform yarn tension as well as a uniformly twisted thread. The yarn storage with a yarn storage disk can be defined as a thread brake without inertia.
Twisting spindles for multiple filaments or yarn without yarn storage disks require in general a forced guiding of the yarn balloon (U.S. Pat. No. 2,127,921; U.S. Pat. No. 2,609,652; German Patent 1,268,031). Such twisting spindles react very sensitively to changes of the inner yarn tension (removal tension) or the outer yarn tension (tension within the yarn balloon) which often results in breakage of the yarn. A forced yarn guide in the area of the yarn balloon is usually only suitable for very breakage-resistant yarns.
The solution disclosed in German Patent 1,268,031 takes into consideration this forced yarn guide. According to this document the force-guided yarn within the spindle rotor area is guided into a portion of the balloon limiter rotating with the spindle rotor. The compensation of the yarn tension takes place in the zone of the portion of the balloon limiter rotating with the spindle rotor or in a coaxial, cylindrically upwardly extending rotor.
In Swiss Patent 417,418 the storage disk is replaced by a balloon limiter that rotates together with the rotor of the twisting spindle.
In German Patent 37 28 213 a twisting device for a three-for-one twisting operation is disclosed in which the twisting spindle also does not have a storage disk. The yarn exiting from the hollow spindle shaft is guided to the edge of the spindle rotor and from there is transferred to the balloon limiter that rotates in the same direction as the spindle rotor. According to this publication it has been observed that for such twisting spindles the balloon yarn comes into contact with the inner wall of the balloon limiter only when the balloon limiter itself rotates. If this were not the case, the balloon yarn would be in contact with the lower portion at the outer mantle of the protective pot (compare also German Offenlegunggschrift 30 25 698).
The storage at the inner mantle of a balloon limiter rotating with the spindle rotor can be easily envisioned as a spatial curve of the yarn (slight spiral form). The balloon yarn, due to air friction, remains in the slot between the rotating spool support that may be rotated counter to the spindle rotor and the balloon limiter, respectively, the protective pot of the spool support, i.e., the yarn is slowed down. The spatial curve of the yarn begins at the outlet opening of the spindle rotor and ends at the transition of the highest contact location at the balloon limiter into a balloon yarn guide eyelet positioned at the spindle cover. In the case of spindles without a spindle cover the spatial curve ends directly at the balloon yarn guide eyelet.
Upon startup of the spindle the balloon yarn hits a standing air column which results in a slow-down relative to the rotating balloon limiter. The spatial curve of the yarn balloon extends over a certain circumference of the spindle with the consequence that the balloon yarn may wind spirally about the outer circumference of the inner protective pot of the spool support which rotates counter to the balloon limiter. Due to the friction of the threads the balloon yarn would be constricted resulting in breakage of the thread.
It is therefore an object of the present invention to provide a twisting device with a balloon limiter rotating with the spindle rotor for a multiple twisting operation (two-for-one and three-for-one) in which the rotating balloon limiter serves as a storage zone without the disadvantage of thread constriction about the spool pot during the startup phase of the spindle.